


Gut Instinct

by Dusklatte



Series: Undoing [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Accidental Voyeurism, Also I may or may not turn this into a series because hoo boy i love me a series, Arguments, Chapter 1 is just build-up, Comfort, F/M, Felix also just wants to protect byleth, Including being turned on by Byleth's teacher glare, Jealousy, Love Bites, Post-Coital Cuddling, Post-Time Skip, Seteth wants to protecc Flayn from indecency, Sexual Content, Sexual content to be in chapter 2, So about chapter 1 being build up and 2 containing sexual content... everything is build up now lol, So how about that slow build up eh?, Sylvain has some Weird Kinks, Sylvain pining for Byleth, Teasing, They finally do it!!!, They'll fuck eventually though;;;, Vaginal Sex, convenient doors which have a broken lock are convenient, rip felix;;;, spoilers for blue lions route
Language: English
Status: Completed
Published: 2019-08-26
Updated: 2019-10-18
Packaged: 2020-09-27 09:34:30
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 8,110
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20405545
Author URL: https://archiveofourown.org/users/Dusklatte/pseuds/Dusklatte
Summary: Sylvain had a weird feeling in his gut ever since she returned to their lives. It never went away - but grew worse whenever he saw her with Dimitri.





	1. Witnessing what can't be unseen

**Author's Note:**

> I made a poll on Twitter asking about if I were to write a couple which _wasn't_ Claude/Byleth, and though there's still like 6 days left for it, Sylvain quickly ended up leading. In second place is Hubert-  
But I decided I'd try to write some stuff for precious Gautier bby~
> 
> The poll is [here on my Twitter](https://twitter.com/ClaudeEmblem/status/1165707507706322946?s=20) if you want to <strike>force me to write something other than</strike> influence what I write aside from Byleth and Claude~

Sylvain couldn’t shake a strange feeling which had been building in his gut over the past few months. He had decided, for some reason, to see if it was worth attending the class reunion on the day of the Millennium Festival. Somehow, he had encountered Felix and Ingrid along the way. Somehow, he found out that of anyone, _Dimitri_, who was supposedly executed for his uncle’s murder, was alive.

However, none of that was the reason for the weird feeling.

It was his former Professor’s presence. She had been announced as one of the casualties of the battle for Garreg Mach five years previously. He, and the other Blue Lions (and even some of the Golden Deer) _mourned _losing her.

Any time he would sit to have a drink of tea with any female, it wouldn’t be as stimulating as when he had shared tea with the Professor. Some of the times, he found tea being thrown into his face because he accidentally called his partners ‘Professor’ or ‘Byleth’. He even found himself intentionally losing items, in the hope that she would appear to return them.

But that never happened. Not once in those five years.

Yet she was there. Alive, at Dimitri’s side. She hadn’t aged a day since that battle. She even possessed the same wounds she had received in that fight!

_He almost thought he had seen a pair of ghosts on the battlefield._

Even now, months later, he still had an unsettled feeling in his stomach. It still didn’t feel… Real. There couldn’t be the chance of her surviving at the bottom of a cliff for five years, yet… she did. She shouldn’t have remained the same age as before, yet… she did.

Whenever there was something impossible, _she did it!_

Though the feeling was constantly there, and never improved… There was only one time where it grew worse. _A._ M_illion. Times. Worse._

He had decided to go to the Cathedral to pray for those who had fallen in the most recent battle. It was uncommon to see him in there, but one of the losses _was _someone who he saw almost like a second father-figure to him. Rodrigue’s death was a heavy weight on everyone’s shoulders.

However, when he finally reached the pews, facing towards the crumbling stained glass at the far side… he saw two figures.

_Dimitri, and somebody wrapped up in his excessively large cloak._

He took some steps forward, trying to ignore Dimitri and the other person, until he heard voices. Voices which told him who exactly was under that cloak…

“Dimitri… Please… Please don’t do that again… I know you’re haunted by the ghosts, but… If you die… What about those of us still living? What about me?”

“Professor… I… I apologise...”

Sylvain could feel his heart sink, and his stomach be twisted. Twisted into a million knots, and weighed down by a boulder. _Byleth and Dimitri… Were they… Were they a…?_

As much as he wanted to pray for Rodrigue to find peace now that he was with the Goddess, he couldn’t do it. Not with those two there… Not if… they were a couple.

All Sylvain could do was turn around, and briskly make his way out of the Cathedral.

* * *

* * *

It had turned to Monday morning, and everyone in the army had gathered for tactics and skill training. For the first time since the group had reunited, Dimitri had also been in attendance.

_Sylvain, however, was not present._

He had remained in his old dormitory room, sat at the rickety old desk. His elbows were getting splinters as he hadn’t bothered putting his armour on, and all he could find himself doing was inhaling the musky, damp smell of the rotting wood as he tried to shut the images of what he saw at the Cathedral out of his mind.

_Dimitri and Byleth. _

_Dimitri. And Byleth._

_The Boar Prince and HIS Byleth._

“Damn… What am I even thinking?” He muttered, before sitting up, stretching, and putting his feet up on the desk instead of his elbows. “I should be happy for them if they are together… Not feeling… like I’m the one who should be getting all of the attention.”

_Maybe that evening he should go down to the local village… Have a drink or two and see if there is any woman interested. Just to get his mind off things. Just so… he could forget what he saw in the Cathedral._

Sylvain remained balancing precariously on the chair for a while after that, just thinking about how what he witnessed had been enough to turn the feeling in his gut into something dreadful.

Eventually, there was a light tap against his door. It reminded him of the many times where Ingrid had come to talk to him as a friend, just to turn into a lecture about his ways of treating women. He had a feeling this would be something similar, just about his absence from the tactics meeting instead of his manners.

_May as well go through with it, it might distract from that feeling and those thoughts for a few minutes._

“The lock is broken… You don’t have to knock.”

A slight creak filled the room as the door opened, and he braced himself for an impending lecture. But no… Instead, the smell of one of his favourite teas wafted through the air, breaking through the disgusting damp smell. One of his eyes pried open, and he realised that…

_It was definitely not Ingrid who was visiting._

“Sylvain… I was worried about you, you know… I thought that maybe you would be here, and I would bring some of your favourite tea.”

Reluctantly, Sylvain rose from his chair, and approached Byleth as she stood by the door. A half-hearted smile was on his face as he looked at the tea. “I thought there wasn’t any more Bergamot tea in the monastery… There wasn’t any in the dining hall when I went there last night...”

“You don’t think that I wouldn’t keep some of my favourite former student’s favourite tea, do you?”

“Favourite former student… Hah, that’s funny, Professor...” Sylvain backed up into his room, and sat down on the new bed which had replaced the one which had been plundered at some point over the past five years. “You would’ve thought that _Dimitri _was your favourite, based on how you’ve been interacting with him since you came back...”

Sylvain then closed his eyes as he heard Byleth walk into his room, place the tray of tea on the old desk, before dragging the wooden chair across the floor to beside his bed. She sat on the chair backwards, so that her legs were at either side of the back of it, and her arms rested on top of it.

“Tell me, Sylvain. What makes you think that Dimitri is my favourite?”

“Oh, I dunno… The pair of you were declared dead a few years ago, yet both reappeared on the day of the Millennium Festival. You’ve hovered around him _constantly _over the past few months. And yesterday afternoon-” Sylvain’s gut felt as though it was being shredded to pieces. “And yesterday afternoon, I _saw _you both. You were under his cloak, and were comforting each other! It easily looked like something _extremely _intimate…”

A quiet ‘oh’, filled the room, before suddenly, Sylvain felt a soft yet calloused hand take a gentle grasp of his own. He pulled his hand free. “I get why you would think that way, but… Answer my questions quickly. Who did I give extra lessons to at completely inappropriate times when I was professor of the Blue Lions class?”

“That would be me...”

“Who did I let off from extra assignments over some flattery which their friends thought was hopeless for them to do?”

“Again, me...”

“Who did I invite for tea parties most often when they were a student? Who is the _only _person I have shared tea with since I returned a few months ago?”

Sylvain didn’t want to answer, but he knew what the answer was going to be.

“It is you, Sylvain. It was drilled into me pretty early on when I first became a teacher that playing favourites was an absolute no-go. Yet I would still favour you whenever possible,” Byleth explained, before sighing. “Besides… Dimitri is not ready to feel love. He’s had a tough time over the past nine years, since the Tragedy of Duscur. _Especially _over the past few years. He is barely just able to open himself up to the thought of accepting that people wish to be his friend – I feel that love would be far too much of a push, and far too soon.”

Each word which Byleth said… It had provided him some comfort, despite the doubts still ringing in his head. But he knew she had to be right… The painful feeling subsided when her soothing tone reached his ears.

“Professor… No, Byleth… Why did you even favour me when I was your student? And now, even?”

Byleth brought her hand up to her chin, and she hummed thoughtfully. “Hmm… Well, I could tell that you had a tough past almost straight away. That was explained by the whole situation with… your brother. And… Though people warned me of it, I couldn’t help but find myself charmed by your smile. Even my father told me that he was concerned about the fact that I always smiled back at you when you smiled at me. Though your words to other women felt somewhat… forced, for some reason, it always felt genuine when you spoke to me.”

Sylvain finally opened his eyes, and noticed that Byleth was giving him a concerned look, and had reached her hand out for him. He accepted her hand.

“Come on now, Sylvain. We don’t want the tea to go to waste, do we? Maybe I can show you where the secret stash I have just for you is afterwards.”

Before she could lead him over to the tea on the desk though, he felt some words caught in his throat. And he _had _to say them before they got distracted by the drinks she had kindly prepared for them.

“Byleth… Do you think that _I’m _like Dimitri? Not… ready to feel love?”

She hesitated for a moment, which made him fear the worst. “No. You’re not. You’re certainly capable of feeling love… You just need the right person _to _love,” she began, before she started laughing. “Look at me… The woman who was emotionless until a mere few months – years – ago… And now I’m some sort of relationship advice provider.”

“I’m… glad you think I’m capable of love, Byleth,” Sylvain was finally able to wipe the concern of his face, and had replaced it with his signature smile and wink. “Because I think I may know who the right person for me is. If you’ll have me, of course...”


	2. Unusual ways of showing affection

**Summary for the Chapter:**

> Sylvain awaits Byleth's answer to his request.

**Notes for the Chapter:**

> This was going to be just two chapters, but my imagination has kinda died over the past week as I'm tired from work. I just need to rest up a bit and should be back in the swing of things, so expect another update for this at some point this weekend? :)

Sylvain had to admit – the pale blush decorating Byleth’s face was a thing of beauty. Yet, she still hadn’t given him a response… The frown on her face which formed in response to his hopefulness confirmed his fears.

“Hah… I knew it. It’s all your way of softening me up, right? Tell me that I can love, and when I tell you how I feel, you just reje-!” Before Sylvain could finish what he was saying, Byleth had grabbed hold of his shirt and pressed her forehead against his. “Uh, what are you…?!”

“Sylvain Jose Gautier. You need to shut up and stop over-thinking things. For someone who is a self-proclaimed ladies man, you’re really _not _good at reading a woman’s emotions. Hell, _I’m _not even good at showing emotions, but I thought I was letting you know how I feel about you quite obviously up until this point. I frowned because you didn’t even _notice._”

“Wait… You mean to say that you also… You would have…?”

“Yes, Sylvain. To answer your question, I’ll have you. I’ll be all yours in return,” she whispered, before leaning in and pressing her lips against his.

_For the first time in such a long time, Sylvain didn’t have the horrible feeling in his gut. It had been replaced by a strange, fluttering feeling._

Slowly, Sylvain did what he had been _longing _to do from the day she became his professor, and the day she came back from the dead. Even the day they shared at the Goddess Tower… He had been wanting to do this so many times, but never felt capable of doing until now. His hands snaked around her back, under her coat, before taking hold of her ass and _squeezing._

_He had always wanted to know how she felt under all of those layers which covered her back._

“Ah-! Careful!” Byleth finally grinned, giving Sylvain a playful hit on his chest as he squeezed again. “Don’t make me use my teacher glare to make you stop.”

Sylvain sighed, yet despite sounding defeated, he continued. His hands trailed from her backside to the top of her thighs, and as he did that, he shook his head and leaned into her ear. “That threat is useless against me, Byleth. If anything, the only reason it made me stop my advances as a student is because it really turned me on and I didn’t want to embarrass myself. Now though, given the situation... it will just spur me on even more.”

Now it was Byleth's turn to sigh. She had to admit – Sylvain had just tossed her trump card for slowing his advances down right out of the window... Hell, she’d just gone and sped them up.

She had always liked Sylvain, even when he was her student. But professionalism (and Seteth) meant that she couldn’t act on it for a majority of the time. Once she began to feel and understand emotions more than she ever had done before, she had started to fantasise about spending a night with him – obviously not allowing it to intrude in her work.

Those fantasies had always been slow, affectionate. Sylvain being as smooth as ever, his smile making her melt into his touch. The current situation? Much less so. It was more eager, hands-on, with clear signs of built up stress and relief. He was grabby – borderline desperate for his chance to have her.

Noticing that she now appeared quite flustered, Sylvain smirked and pressed his lips against hers. Her mouth was dry. Awfully dry. He wasn’t going to have that though...

Slowly he pulled back, and winked once more. “Just a second, I'll continue what I started when I've had a quick drink.” He went over to the desk where she had placed the tray of tea, an idea forming in his head when he realised that though she had brewed a pot of tea, there was only one cup... “Hmm, do you want some tea, Byleth?”

He heard a creak as she sat down the bed. “Well, that _was _one of my main reasons for coming here...” He then grinned. He had figured out that she had wanted them to share the tea in that one cup... So he was going to share it with her.

_Just... not in the way she was expecting. _

He poured some of the tea, and took a sip as he turned around. She raised an eyebrow as she folded her arms – he figured she likely thought that he was teasing her. He then took another sip, placed the cup down, and approached her.

Byleth’s face was filled with confusion as he then pulled her to her feet, and he firmly took hold of her waist. “Sylvain... Are you trying to mess with me? Stopping me from getting some tea?” Yet, despite what she had said, she threw her arms around his neck.

Sylvain shook his head. He then leaned in and pressed another kiss to her lips. She could smell the bergamot tea quite strongly, and could even taste it on his lips. She then opened her mouth in surprise when he pulled her hips closer to his own, which is when he put his little plan into action.

He hadn’t swallowed the second sip of tea he had taken.

Byleth was definitely caught by surprise when she felt the warm tea pour into her mouth from Sylvain's, and her face was a vivid shade of red. She could feel a bit of the liquid dripping from the corner of her mouth, so she pulled one of her arms back to wipe it from her chin.

“_Sylvain! _That was... um... interesting...”

“Really? Because I think that’s going to be my favourite way to have tea with you soon. Especially if you keep trying to trick me into having tea with you, but only bringing one cup.” _That, and watching the tea pour out of her mouth… it got some rather lewd thoughts into his head. _“Now come here, I’ve got something more which I want to do...”

He then moved his hands upwards, and started fiddling about with her armour. _Another reason he was so happy he didn’t leave his room that day – he didn’t need to bother with his own armour as he wasn’t wearing it! _

Deftly, as though he had been in practice for this exact moment (which he had been, considering that Fódlan had been at war for the past five years) he removed each and every buckle, clip and fastening which kept her armour on her body. One by one, her gauntlets, elbow guards and breastplate fell down onto the wooden floor with a loud thud. He then reached out for the belt keeping a dagger around her waist, and they were briskly tossed aside.

“Damn, Byleth… You looked good with your armour, but you look even better without it… Why not take it off on your rest days?”

“You never know when you need to be ready for a battle, Sylvain…”

“Okay, but what is the point? There’s no need if I’m going to be keeping you busy on your rest days from now on. Hell, maybe there won’t even be a need for clothes...”

“I- ah- Um...” Byleth was completely lost for words then, her face bright red. _He was definitely implying what she thought he was implying. _“D- Damn it, Sylvain! Just finish what you were doing before I die of embarrassment...”

Sylvain felt triumphant. He had the often stoic, typically serious Byleth a blushing mess in his room. All the more reason to get her clothes off _as soon as possible._ He then pulled her over to the chair which remained by his bed, and made her sit down on it. He then kneeled down, and removed the armour covering her knee, before allowing her boots to join the growing pile of mess in the room.

“Whoa. Your feet are small, professor…” He gently stroked across the lace stockings which she was almost never seen without, before his fingers trailed up her leg. “However… I...” He shifted closer to the chair. “Have other priorities.”

Before Byleth could react, or Sylvain could continue his advances…

The door swung open. “Damn it, Sylvain! We could hear loud noises from the training grounds! What is going-” The pair flinched at the sound of Felix’s voice, before there was an awkward silence. “… Fucking hell...”

The door slammed shut again. Byleth’s face grew even more red, and Sylvain had to hold back a chuckle. “I, uh… Forgot about the door not being able to lock...”

“_No kidding! _What if Felix goes back to the others and-!”

“Ah, who cares if he tells the others that we’re going to be fucking? It’ll just let all of them know that you’re mine… _Especially Dimitri..._” He whispered the last part, but the parts preceding it were enough to make Byleth start choking at the lewdness, and have to awkwardly rub her legs together, because his tone of voice was rather… _hot._

Because he could see that the walk-in had greatly bothered Byleth, he pulled her up off the chair and propped it up against the door, just under the handle. When he was sure it wasn’t possible to open unless the chair was removed, he turned back to her with a devious smile.

“Ahem… Now that we have some privacy, it’s time to continue where we were up to. How about, say… We get rid of those shorts of yours?”

**Notes for the Chapter:**

> Lmao I can imagine Sylvain having a few normal kinks like dirty talk but also some strange kinks and stuff like the whole 'kissing with tea in their mouths' and Byleth's teacher glare-
> 
> Meanwhile, in the training grounds...  
Felix: THEY ARE FUCKING. NOT SPARRING OR FIGHTING ENEMIES. THEY. ARE. FUCKING.  
Most of the Blue Lions: lmao no way Sylvain would end up with the professor  
Ingrid: i'M GONNA FUCK SYLVAIN UP-


	3. Insatiable

**Summary for the Chapter:**

> Felix tries to get rid of the image burned into his mind, whilst Sylvain finds out something which Byleth enjoys.

The training grounds at Garreg Mach were mostly silent. They had been quiet to begin with, when Dimitri had decided to join his allies in their practice, but had become quieter still when suspicious noises like armour being tossed against a wall or floor began to echo around from the direction of the dormitories.

Everyone was confused at the noises, but almost nobody feared what it could be. The only people absent were Sylvain and Byleth, and it they had somehow managed to end up in an unfortunate encounter with thieves trying to sneak in, they could deal with it.

Annette persuaded Felix into checking as a ‘just in case’.

_Or rather, she kindly promised to feed him some of her home-made sweets if he didn’t go._

So, Felix had gone to investigate. When he returned, his face was dark. Angered. Nobody knew how to take that as a response to the strange noises.

“Boar!” Once he had stepped into the main area of the training grounds, he picked up a sword and began to glare at Dimitri, who was having some of his previously untended wounds cared for by Mercedes. “As soon as she’s done, pick up your weapon. We’re going to fight.”

Dimitri returned the glare, his one eye appearing colder than it ever had done before. He took hold of his lance, and slowly rose to his feet once Mercedes had finished covering a disinfected wound on his arm with a bandage. “What’s gotten you so riled up, Felix?” Despite his words sounding calm, his face clearly said otherwise. “Answer me, or I will not fight you.”

Despite his words, Felix still slashed towards the prince, who deftly blocked the attack almost with a flick of his wrist. “I shouldn’t have to explain! Can I not _want _to fight?!”

From the sidelines, Ingrid was shaking her head as she gave off an exasperated sigh, and Ashe was biting his lip at the loud clashes of metal. Dedue was silent, leaning against a pillar as the fight quickly ramped up from a spar to a desperate attempt to get Dimitri to retaliate.

Eventually though, it was clear that Ingrid had enough of the situation. She picked up her own sword, and put it between Felix’s sword and Dimitri’s lance. “Felix. You need to calm down! What has you acting so recklessly?!”

“Oh, I don’t know… Maybe just witnessing Sylvain and his philandering ways getting the Professor to strip off in his room had something to do with it?!”

The training grounds had been quiet. Now they were well and truly silent.

Even Dimitri seemed taken aback by what Felix had said, judging by his slightly agape mouth and his lance falling to the ground with a loud clatter. “Are you implying that _he, _of _anyone_, is-?!” Dimitri had grabbed hold of Felix’s shirt, before letting go when he remembered that Byleth had asked him to at least be more gentle with his allies who were willing to fight by his side. He stepped back, and laughed quietly.

_It reminded his former classmates of the borderline psychotic laugh he had when Edelgard revealed herself as the Flame Emperor. Just… calmer._

“Perhaps you misread the situation, Felix. I mean, the Professor had to deal with his… mannerisms quite a bit when he was a student. She, of anyone, would surely not allow herself to be swayed by him unless she truly wished to be with him.”

_Trust Mercedes to bring sense into the conversation._

“You say that, but that image is burned into my mind, and I can’t see the situation being _any _different than what I said it is. Now come on, Boar… Fight me!”

* * *

* * *

Unlike what a majority of the former Blue Lions students thought, Sylvain was indeed stripping Byleth of her clothes in his room.

At present, she was simply wearing her lace stockings, her sleeveless black shirt, and underwear. Sylvain had made quick work of her shorts, and had discarded them across the room a few minutes previously.

She also happened to be pinned down to his bed by her wrists as he decorated the exposed skin of her jaw and throat with kisses. She had to admit that she wasn’t absolutely keen on not being able to use her hands <strike>to tear his shirt off</strike>, but she was absolutely relishing the feeling of his mouth and tongue on her skin.

After a particularly rough bite on a patch of skin near to her collarbone, followed by his soothing tongue, a quiet moan escaped her lips.

_Sylvain had heard a few women in his time, but none of them sounded as angelic as Byleth did then._

“So… You liked that? I can give you more, if you want...” He glanced up at her face, and realised that her face was completely flushed and she was looking at him through her lashes. “Or… would you like a little something...” One of his hands freed its grasp of her wrist, and trailed down to her breast. “More?”

“Both.”

Sylvain cocked one of his eyebrows at her determined sounding response. He wouldn’t argue with her though – if he could continue to mark her to keep people like Dimitri away from her, whilst simultaneously pleasuring her… He would take that opportunity in a heartbeat.

“If you say so~” His voice was almost like he was singing as he leaned into her neck once more, and continued to leave a trail of love bites. He also made sure to be more rough in the areas where he knew that her clothes wouldn’t cover… He needed to make sure that those bruises were clear to everyone that she had been claimed by him.

Carefully, he hooked his fingers under her shirt in order to pull it off her. The lack of sleeves certainly made things easier. The fact that it tore easily? Easier so.

“Damn… Should’ve known better than to trust clothes which were at left in a closet for over five years to gather dust...” She mumbled when she noticed that Sylvain found the situation amusing. “I’m going to have to borrow one of your shirts when we’re finished here, Sylvain.”

He winked with a grin on his face. “Sure. _When _we’ve finished. Not that anyone will be up and about when we do.”

“You’re insatiable!”

“And you love me for it.”

“I- Yes, Sylvain. I do.”

**Notes for the Chapter:**

> They're gonna fuck... at some point... I'm kinda enjoying writing the slow build up lmao-


	4. Top to bottom

**Summary for the Chapter:**

> Byleth knows that Sylvain has experience with women. But had he ever had the experience reciprocating?

**Notes for the Chapter:**

> I????? Don't even know?????
> 
> I've spent the past few days trying to get this written but have only been able to do a few sentences at a time so it might be a bit all over the place? Because what the hell even is proof reading or beta reading-

Sylvain was quick to pull his blue dress shirt over his head, before he did his best to launch it towards the chair keeping the door closed. “So you don’t forget it on your way out~” he winked, before leaning down and pressing a kiss to one of her pert nipples. “And this is so I don’t forget to leave my mark on you...” he mumbled quiet enough for her not to hear him over her loud, flustered sigh.

“S… Sylvain...” her voice eventually came out as a whisper, her free hand cupping his chin and pulling him up towards her face.

“Hmm? What do you want, Byleth?” He nuzzled his nose against hers, his lips lightly teasing her own by brushing against them. “More attention elsewhere? Or… is there something you want to try out? I’m open to new things in the bedroom, after all.”

“Ah… well, I...” She began, watching as he looked at her closely, wondering what was on her mind. She took the opportunity which was set out before her. All it took was using her free hand to take hold of one of his, before hooking one of her legs around his. She tossed them over, so that now, Sylvain was underneath her. “I can tell you have… experience with trying to please a woman, based on your actions so far...” She mumbled, bringing one of her hands up to some lose strands of green hair and tucking it behind her ear. “But I can’t help but wonder – is there anything that _you _want?”

“Obviously, I want you!” He grinned, wrapping his arms around her shoulders and pulling her down to him. “Is there anything more a man could want in a situation such as this than sleeping with the woman he has longed for since laying his eyes upon her?”

A small smile formed on Byleth’s lips, before she pressed a soft kiss to his lips. “I think you’re misinterpreting my question… I want to know how _I _can pleasure _you, _before you get too carried away with pleasuring me. I’m inexperienced, so I’ll need some guidance.”

A quiet ‘oh’ escaped Sylvain’s lips, a slight red flush forming on his face. He never had a woman proposition _him _before… It was always him propositioning a woman. It felt… It felt like his body was burning up in desire.

_Byleth and her suggestion were pretty damn arousing._

“So? What would you want, Sylvain? I can tell you want me to do something, after all...” Her eyes drifted towards his trousers, before snapping back up to his face when she felt him chuckle.

“Hmm… How about you take off your stockings?”

“I was going to be doing that anyway!” She playfully hit his chest, before shaking her head. “You know what, if you’re not going to take this seriously, I’m just going to make an educated guess which you can’t complain about.”

All that Sylvain did was smirk, and remain silent.

He saw a variety of emotions go across her face in those few moments she realised what he was doing. He was definitely used to her being rather straight-faced with the occasional smile, but he liked what he just saw. Her mouth open with shock, followed by her brow furrowing and her lips forming into a pout.

“Fine, if that’s what you want...” Byleth eventually whispered, making true of her promise of removing her stockings (as well as the rest of her clothes as a bonus), before leaning down and pressing a gentle kiss to his lips. He couldn’t tell at that moment what her plan was, but it didn’t take long for her knee to give it away.

She had moved her legs slightly, so that rather than be sat over both of his legs, she was straddling just one. Following that, she had distracted him with the kiss as she pressed a knee against the particularly visible erection in his trousers. It… it made things pretty tough for him.

_Over five years he had waited for this moment, and he didn’t want to ruin things with her by rushing, and causing her pain by being too hasty._

“Sylvain~ Open your eyes...” Byleth sounded as though she was singing to him. Not to mention that he didn’t remember when he had closed his eyes. Moments later, her warm hands cupped both sides of his face. “Too much? I’m sorry...”

He opened one of his eyes slightly, and smiled. “Nah, I liked it… I mean, it’s hard to hold back when the hottest lady at Garreg Mach is grinding against you...”

“What reason do you have for holding back?” Byleth’s question made his throat bob, and his mouth turn dry. “I’ve never really been one for taking my time in the past. I don’t see any reason to change that now.”

A strained groan made it past his lips as her knee pressed into him once again, and once more, he found himself struggling to hold himself back. “Byleth, _please…” _His voice came out as more of a whine than he intended. “If we go too fast-!”

Byleth cut him off with another soft kiss. “I said I was inexperienced before, not completely oblivious. It’s unfortunate the amount of sex talk you’re exposed to when growing up in a mercenary group. However, when you find yourself _grinding against the hottest man at Garreg Mach...” _Her tone mimicked his from earlier, turning his face a similar red to his hair. “You end up awfully wet.”

_With those five words, Sylvain had broke._


	5. No more holding back

**Summary for the Chapter:**

> Though Sylvain is desperate, he still does his best to be a gentleman to the woman he loves.

**Notes for the Chapter:**

> Drumroll....  
It's time! They finally do it!!! Woo!!!

He struggled to find a comfortable place to put his hands, but he knew for a fact that he wanted to keep hold of her and never let her go. Byleth’s tone had been so calm and yet _so sultry, _he knew that his mentality of holding back had now been tossed out of the window.

Sylvain had gone from a man to a beast within seconds.

Eventually, he took hold of her leg which rested between his own, and shifted it so that she was now straddling both of his legs. During this moment, he leaned in for a kiss which she so easily melted into… The way her hands positioned themselves on the side of his head, their lips, teeth and tongues clashing as he moaned… _Fuck, he’d never loved her more than he did right now._

Almost in a panic, he went about unfastening his trousers as she leaned further against him, pushing him down onto the sheets of his bed, her gorgeous breasts pressing up against his own chest, her breathing turning ragged…

He let out a sigh of relief when he freed his erection from his trousers, and Byleth chuckled quietly. “That desperate, Sylvain?”

“You’ve got _no _idea...”

Finally, he knew here he wanted his hands. One had grew to rest on her hip, whilst his other teased below her stomach, but just above where she wanted his touch most. He stroked his fingers against some of the scars which covered her skin, surprised at the both soft and muscular feeling of her body. “For someone who is desperate… You sure know where not to touch...” she muttered against his lips as he continued this motion, a slight puff of air coming from his nostrils as he smirked.

“Well, I can’t just pull you down onto my cock and fuck you, can I? I’ve got to at least make sure you’re just as desperate as I am...” Byleth’s eyes widened at his word choice, before she whined and bit her lip as his fingers moved lower, and gave a slightly teasing tap against her wet folds. “Fortunately...” Byleth gasped when she suddenly felt his finger push into her, and did a few experimental pumps. “I think you, Byleth Eisner, are more desperate than I am.”

Byleth almost glared at him when he pulled his hand away from her, and proceeded to lick his damp finger. She certainly wasn’t happy with the sudden intrusion of her body just for it to go away again, but at the same time… she wasn’t dissatisfied either.

Gently, Sylvain pulled her in for another kiss – albeit much more careful than previously. He then moved his hand back down once more as he savoured the taste of bergamot tea on her lips, his mind making up that if she drank that tea more often, she would surely become his favourite treat.

Rather than touch her body, however, he took hold of his straining cock and used his hand which had remained on her hip to pull her down to meet him.

Byleth hesitated slightly in the kiss when she felt the tip of him press against her, leading to him stopping for a moment. Despite this moment of her being unsure, she then smiled and nodded. “You know if I didn’t want this, I would have either said ‘no’, or left the room?”

“I… Good, I didn’t want to go into this if you didn’t feel ready.”

“Ah, such a gentleman, Mr Gauti- Oh! Ohhh...” Byleth cut herself off with a gasp and a moan as Sylvain slowly pulled her down onto him, the feeling of his length within her being both foreign yet comfortable.

Carefully, Sylvain sat upright once Byleth’s hips met his own, before pulling the woman into a tight hug. Now that she was here… Now that they were finally together… He didn’t want to let go. He felt a flood of happiness through his body when she reciprocated the tender action.

After the moment of jitters and delight, Sylvain’s hands lowered to take a firm grasp of her hips. He raised them slightly, making Byleth moan quietly against his shoulder, before pulling her back down again.

Soon enough, they fell into a rhythm. Byleth picked things up quickly, so she started moving her body without Sylvain’s support, him instead pressing more love bites to her neck whilst keeping hold of her hips. At one point, her nails began to dig into his back, scraping down his skin and sending shivers down his spine. That, in combination with the lewd noises their bodies were making, and their lustful moans and whines in response to what they were doing…

Sylvain felt himself nearing his limit. Byleth clearly was reaching her own too, as her movements grew somewhat messy and unsteady. He did his best to help her out by pushing his hips to meet her half-way.

“Damn, Byleth… I think that I-”

“So- So am I...”

After a few more pushes, Sylvain felt himself so close, and his brain felt like it had been singed. All his thoughts were completely incoherent… except for one. “I l- love you...” He whispered frantically into her ear as he came, her body following moments after.

They remained silent, only their ragged breaths filling the heated room. Sweat was coating both of their bodies, but neither of them really cared as Sylvain pulled himself together, and tightened his embrace of Byleth.

“I really mean it, Byleth… I love you. I don’t think I’ve been more serious about anything in my life...” He muttered into her skin once he felt her head lift of his shoulder to instead press her face gently against his, her hands carefully stroking his cheeks.

“Sylvain… I love you too,” she smiled at him, before pressing a kiss to his nose. “I’ve never felt much in my life, and emotions are rather difficult for me… But I know for certain that I love you too.”

After a few more moments in the loving embrace, Byleth pulled herself away from Sylvain before shifting herself to beside him. “I’m tired, do you mind if I lie here for a while?”

“Do you want to clean yourself off first?”

“… Sure. It’s probably not a good idea trying to sleep when all I can feel is the mess you made between my legs...”

“H- Hey, you could have asked me to come elsewhere, but-”

“I don’t mind, Sylvain… Though perhaps if you have something in here to clean up with...”

Sylvain’s face was flushed red as he did his best to sort out his trousers, before reaching into his closet to grab hold of another shirt. In the process, he grabbed hold of a towel which he had in there and tossed it over to Byleth.

Out of modesty (which Byleth thought to be quite amusing, since he had seen her naked mere moments ago) Sylvain didn’t watch as she cleaned herself up. He instead put his clean shirt on, his head going to a million different places.

_What if she fell pregnant after this? Sure, she said that she didn’t mind that he came inside of her, but they had only recently confessed… having a child, especially when they were fighting at war… that was far from either of their priorities. Plus, neither of them had discussed it and probably wouldn’t have the chance for a long time!_

_But at the same time… If she did fall pregnant, that would keep the likes of Dimitri and Felix away from her. He’d have proof that she was claimed, as soon enough her stomach would be round with his child-_

He had to distract himself from this train of thought _immediately. _

“Sylvain? Has the tea I brought gone cold?” Byleth’s question couldn’t have come at a better time. He went over to the tea on his desk, and dipped his finger into the half-empty cup. He nodded in response. “Damn… I could really do with some tea about now.”

“How about I go and make some whilst you clean up then?”

Byleth laughed quietly, before he felt a quick kiss to his cheek from behind. “Why not?”


	6. Was tea worth all this?

**Summary for the Chapter:**

> Sylvain gets himself into quite the situation when all he wants to do it make Byleth the tea that she had asked for.

**Notes for the Chapter:**

> Last chapter for this!!! But I'm gonna write some follow up because why not-

Sylvain felt strangely refreshed as he made his way down to the dining hall in the hunt for tea and hot water. Perhaps it was down to the evening breeze cooling down his warm, sweat covered skin. Maybe it was down to the fact that there was no longer a feeling of heaviness in his chest, nor the horrific feeling in his gut that had been plaguing him until the moment he confessed how he felt to Byleth.

He still found it a miracle that Byleth had accepted him too. After how he had acted with women in the past, and the scene with Dimitri in the cathedral... The fact that she had embraced _him _was an absolute mystery.

When outside the doors of the dining hall, Sylvain froze. He could hear his allies all chatting together... he could especially hear Ingrid telling Felix off. He gulped, recalling the moment from likely less than a mere hour ago where Felix had walked in on him and Byleth.

After a moment, he silently pushed the door open and closed it behind him just as quietly. He didn’t want everyone to notice him slipping in and out with the tea that Byleth wanted... but a frosty blue eye fixating on him when the door closed told him that would not be the case.

Fortunately, Dimitri drew his attention elsewhere when Flayn began calling his name to talk to him about something with Seteth. Sylvain let out a quick sigh of relief, before rushing over to the pantry.

When he heard the hushed click of the door closing, he made his way over to the shelves which held tea. He knew that Byleth had a secret stash of bergamot – after all, she had told him about that earlier – but he couldn’t remember whether she hid it anywhere in particular. He resorted to using some of the tea which there was the most of in the supplies, which he believed was mint.

_Mint matched Byleth’s eyes and hair._

Getting slightly flustered at the thought of seeing his mint-haired lover drinking mint-flavoured tea, Sylavin went to seek out some more teacups, knowing full-well that Byleth would bring up him liking the idea of them sharing one cup and _obviously _want to kiss again.

_Not that he minded kissing her. He lived for it._

Once successful in his search, he sighed in relief. Hot water was luckily much easier to access than everything else he had looked for, meaning that it wouldn’t be long until he saw Byleth again.

He was stopped before he could get that by a blade being pressed to the back of his throat.

“Damn it... I hoped it was an _actual _intruder that we heard, not _you, _Sylvain.” The blade was pulled away when Sylvain turned around, and he was met with a harsh glare from Felix. “So, what are you doing now? Letting the Professor down lightly over a drink of tea before your next woman?”

A cup shattered as it hit the ground, Sylvain's hand trembling through frustration. “No way. I wouldn’t just- just _use _Byleth like that!”

“Say that to all the other women you've used over the years then. Or are you too cowardly to face that shame?”

“_Shut up, Felix.” _

By that point, Felix had raised his blade again, looking just as agitated as the redhead.

“Make me.”

  


* * *

* * *

  


Byleth had made herself comfortable on Sylvain’s bed, but not after taking some time to look around his room once she had cleaned herself up. When she had been his professor, there had been many a time she had to enter the room to explain to Sylvain that he had to stop bringing in women from outside into Garreg Mach after curfew. That meant that all across the room there were abandoned pieces of female clothing, and makeup.

She smiled at the fact that there was none of that now. The only clothes from a woman in his room now were her own, and for the most part, they were on her body.

In fact, there was only one thing about the room which bothered her – that Sylvain wasn’t back yet. She knew that it couldn't possibly take over half an hour to make some tea…

With a sigh, and without a shred of embarrassment in her body as she wore his shirt, she stood up and left the room to hunt down the room’s primary occupant.

Logically, if Sylvain was to be making tea, he should have gone to the dining hall, so she made her way there first. She noticed that Dimitri was stood outside with Seteth and Flayn, so she decided not to disturb them to ask where Sylvain was, and instead she tried to go inside.

“P- Professor! Have you no- no _dignity?!”_ Byleth froze where she was when she heard Seteth’s horrified gasp, so she rolled her eyes, crossed her arms over, and turned to face him. He had already used his hand to cover Flayn’s eyes, and she was complaining loudly that she was ‘not a child who needed shielding’. “You are wearing a man’s shirt!”

Byleth sighed for what felt like the millionth time, before she noticed that Dimitri had also turned his back, his face a vivid red.

“And the problem is? I am decent, and not exposing anything I shouldn’t. Perhaps it is _you _who has no dignity, Seteth.” After saying her piece, she continued towards the door. She heard Flayn giggling at Seteth’s embarrassment as the door closed behind her.

That then led to her walking in on _another _scene, thankfully not caused by her this time. Unfortunately, Sylvain was involved in this one. He was glaring at Felix as Ingrid was between the pair, holding them apart. Dedue also had hold of one of Felix’s arms, where he was holding a sword.

“You’re a _real _pain in the ass, _Fraldarius. _You seem to think that you’re above _everyone!”_

“And? I’m at a higher position than _you, _Gautier_. _Both in the Kingdom and morally!”

“The hell do you mean by that?!”

“It’s obvious, you fool! You’re just using the Prof-”

The shouting stopped when Byleth approached them, and cleared her throat. Sylvain instantly looked ashamed of being caught in an argument in front of them, but Felix was still looking frustrated, and was looking at anywhere but her. “Please don’t stop what you’re saying on my accord, Felix. How is Sylvain using me? I’d love to know.”

“He always has a motive when he sleeps with a woman!”

Byleth sighed, and went over to Felix before resting her hand against his cheek. The swordsman’s face softened slightly, and in turn led to Dedue releasing his arm. “Hey. You don’t need to worry about me, you know… If Sylvain did end up trying to pull one over on me, I’d kick his ass.”

After a few moments, Felix sighed. “Fine, I trust you… But if he does mess with you, let me know.”

“I will. Thank you for the concern.”

With that, the situation was easily diffused, and everyone besides Byleth and Sylvain went about their business. Sylvain wasn’t sure how to react to how Byleth had been able to get Felix to back off, but… that uneasy feeling in his gut had returned again. The fact that she was wearing his shirt didn’t help either.

_Ah. He was jealous. He finally figured out what the feeling was._

“… Sorry. Felix thought I was an intruder and confronted me when I was trying to get the tea, and it kind of turned into… that.” He muttered, approaching Byleth and pulling her into his arms so that he almost enclosed her. “He thought I was just using you for a quick fuck...”

“Well, I think he probably thought that after what he walked in on before… But at least he now knows I’m a big girl, capable of looking after myself.” She leaned up, and pressed a quick kiss on his jaw. “So… Tea?”

“… Yeah. But the question is… Do we have tea in my room or yours?”


End file.
